Internal combustion engine



Oct. 12, 1965 A. WEBER 3,211,139

INTERNAL COMBUSTION ENGINE Filed Jan. 27, 1964 INVENTOR. ANDREAS WEBER BY Mi ATT RNEYS United States Patent 3,211,139 INTERNAL COMBUSTION ENGINE Andreas Weber, Lorch, Wurttemberg, Germany, assignor to Daimler-Benz Aktiengesellschaft, Stuttgart-Unterturliheim, Germany Filed Jan. 27, 1964, Ser. No. 340,343 Claims priority, application Germany, Feb. 5, 1963, 1) 40,824 12 Claims. (Cl. 123-119) The present invention relates to a suction line installation for mixture-compressing injection-type internal combustion engines with individual suction lines free of throttle valves between the cylinders and a common suction pipe or suction manifold which is supplied with combustion air under normal operation in dependence on a throttle valve. Such types of installations make possible by the utilization of air pulsations or oscillations at particularly good filling of the cylinders with combustion air. On the other hand, difiiculties occur, however, during idling operation, if for any reasons the rotational speed changes, and possibly also if one passes from normal operation to idling speed operation, for example, when suddenly taking the foot off the gas pedal in the motor vehicle. The regulating member of the injection pump is brought instantaneously or immediately to the position thereof corresponding to the changed rotational speed, however, the pro-existing quantity of air is still sup plied to the cylinders because the pressure within the relatively large volume of the common suction pipe or manifold and the individual suction pipes or lines does not adjust itself sufiiciently rapidly to the new value. The fuel-air ratio then becomes temporarily false, and the internal combustion engine does not operate unobjectionably and satisfactorily.

For purposes of avoiding this disadvantage, it is proposed in accordance with the present invention that inlet apertures for the combustion air be provided in the individual suction pipes or suction lines. By this means, the combustion air is able to enter only through these inlet apertures during the idling speed operation by reason of the complete closure of the common suction line or suction manifold by means of the throttle valve. In this manner, the pressure associated with the corresponding new rotational speed can rapidly establish itself in front of the inlet valves because for that purpose a pressure adaptation of only the relatively small volume located between the idling-speed air-inlet aperture and the inlet valve is necessary.

In order to obtain as small as possible a volume between the idling-speed air-inlet apertures and the cylinders, it is further recommended according to the present invention to arrange the inlet apertures within the area of the individual suction lines disposed in proximity to the cylinders.

Furthermore, it is proposed in accordance with the present invention that the individual inlet apertures for the idling-speed combustion air terminate in an idling-speed common suction line provided with a common air-inlet especially with an adjustable common air inlet. Such an idling-speed common suction line or manifold is favorable for the adjustment of the idling speed air quantity for which only a single adjusting member will be necessary in that case.

Accordingly, it is an object of the present invention to provide a suction line system for mixture-compressing injection-type internal combustion engines which avoids by simple and operationally reliable means the shortcomings and drawbacks encountered with the prior art systems.

Another object of the present invention resides in the provision of a suction line system for an internal com- 3,2ll,l39 Patented Get. 12, 1965 bustion engine, particularly a mixture-compressing injection-type internal combustion engine which assures proper matching of the supplied combustion air quantity to the injected fuel under all operating conditions.

A further object of the present invention resides in the provision of a suction line system for internal combustion engines which assures avoidance of improper engine operation especially during idling speed operation thereof.

A further object of the present invention resides in the provision of an intake manifold and suction line system for internal combustion engines which permits a rapid adjustment of the pressure within the system thereby to assure proper operation of the engine even when changing the rotational speed thereof to idling speed operation.

Another object of the present invention resides in the provision of an internal combustion engine of the mixtum-compressing injection-type which is provided with a combustion air supply system so constructed and arranged as to avoid improper operation of the engine by eliminating false fuel-air ratios under all operating conditions.

Still another object of the present invention resides in the provision of a suction line installation for mixturecompressing injection-type internal combustion engines in which the pressure in front of the inlet valves may adjust itself rapidly to that required for proper operation under the given conditions.

Still a further object of the present invention resides in the provision of a suction line installation utilizing a common suction manifold and individual suction lines leading from the common manifold to the individual cylinders which permits a greatly simplified adjustment for the combustion air quantity supplied during idling speed operation of the engine while at the same time assuring proper operation of the engine under those conditions.

Still another object of the present invention resides in the provision of a suction line system for mixture-compressing injection-type internal combustion engines which is so constructed as to avoid effectively any hunting in the rotational speed of the engine.

A further object of the present invention resides in the provision of an internal combustion engine provided with a suction line system so constructed and arranged as to permit a rapid establishment of the requisite pressure necessary for proper operation during idling speed thereby preventing oscillations and fluctuations in the rotational speed of the engine caused by the automatic adjusting mechanism which operates to adjust the fuel injection in dependence on the rotational speed of the engine.

These and other objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance with the present invention.

Referring now to the drawing which shows in the single figure thereof a somewhat schematic view of a suction line system in accordance with the present invention for a mixture-compressing injection-type internal combustion engine, reference numeral 10 designates therein the schematically shown cylinder block of the internal combustion engine. The individual cylinders are schematically indicated by circles designated by reference numerals 11, 12, 13, 14, 15 and 16. The combustion air reaches a common suction pipe or manifold 19 by way of a connecting piece 17 provided with a throttling valve 18 and from there by Way of individual suction pipes or lines 20, 21, 22, 23, 24 and 25 to the corresponding cylinders 11, 12, 13, 14, 15 and 16. The individual suction lines or suction pipes 20 to 25 are provided with inlet apertures 26 to 31, respectively, for the idling speed combustion air. These apertures 26 to 31 are connected with a common idling-speed suction line 32 which is provided at 33 with an adjustable air inlet adapted to be adjusted by means of an idling speed adjusting screw 34.

The fuel injection pump 35 is operatively connected by way of injection lines 36-41 with the injection nozzles 42-47, respectively. The control mechanism for the injection pump 35 is represented in the drawing in a simplified manner: A gas pedal 48 is operatively connected by way of a linkage and interposition of a correcting mechanism operable in dependence on the rotational speed, which is schematically indicated by an apparatus 49 having a centrifugal governor, to the control rack 50 of the injection pump 35. Furthermore, the gas pedal 48 is operatively connected by way of linkage 51 with the throttle valve 18. A return tension spring 52 seeks to drawn the gas pedal 48 into the indicated idling position thereof in which the throttle valve 18 is completely closed and completely prevents the flow of any combustion air past the valve 18.

In this idling speed position, the injection pump 35 supplies the required idling-speed fuel quantity. The idlingspeed air reaches the cylinders 11-16 exclusively by way of the idling-speed common suction line 32. In normal operation the throttle valve 18 is more or less opened and the cylinders 11-16 receive the air requirements thereof essentially by way of the common manifold 19 and the individual suction lines 20-25.

Operation The operation of the suction line system according to the present invention is as follows:

In order to demonstrate the operation of the system in accordance with the present invention, it is assumed that the engine operates at the normal usual idling rotational speed. A vacuum corresponding to the given rotational speed of the engine is then established within the suction system, that is, within the common suction manifold 19 and the individual suction pipes 20-25. If one of the cylinders now does not ignite properly for any reason whatsoever, then the rotational speed of the engine decreases, and the correcting apparatus 49 adjusts the control rack 50 instantaneously or immediately to a larger injection quantity since, considered statically, a smaller vacuum or under-pressure, and therewith a larger cylinder filling belongs to a smaller rotational speed. If the apertures 26-31 in accordance with the present invention were not present and the idling speed combustion air would enter into the suction pipe installation Within the area of the valve connection 17, then it would take a relatively long period of time until the larger pressure corresponding to the smaller rotational speed would have built up within the entire suction line system consisting of the common manifold 19 and the individual suction lines 20-25. During this period of time, the fuel-air mixture would be too rich in fuel; hence, the engine would operate still worse and would decrease still further in rotational speed. In this manner, a disagreeable and unacceptable oscillation or hunting of the rotational speed would be initiated. By reason of the inlet apertures 26-31, the higher pressure between these apertures and the inlet valves in the cylinders 11-16 can build up very rapidly so that an additional decrease in the rotational speed is avoided.

While I have shown and described one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications within the spirit and scope thereof as known to a person skilled in the art, and I therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

I claim:

1. A suction line installation for a mixture-compressing injection-type internal combustion engine having a plurality of cylinders, comprising:

a common suction line including throttle valve means for selectively adjusting the amount of combustion air to be supplied to the engine during normal operation,

individual suction lines operatively connecting said common suction line with the individual cylinders, said individual suction lines being devoid of any throttle valves and including individual fuel injection means disposed therein,

and means independent of said fuel injection means for supplying combustion air during the idling speed operation of the engine including inlet apertures for the combustion air provided within the individual suction lines so that the combustion air is able to enter into said individual suction lines only through said inlet apertures during idling speed operation by reason of the complete closure of the common suction line by said throttling valve means.

2. A suction line installation for a mixture-compressing injection-type internal combustion engine having a plurality of cylinders, comprising:

a common suction line including throttle valve means for selectively adjusting the amount of combustion air to be supplied to the engine during normal operation,

individual suction lines operatively connecting said common suction line with the individual cylinders, said individual suction lines being devoid of any throttle valves and including individual fuel injection means disposed therein,

and means independent of said fuel injection means for supplying combustion air during the idling speed operation of the engine including inlet apertures for the combustion air provided within the individual suction lines so that the combustion air is able to enter into said individual suction lines only through said inlet apertures during idling speed operation by reason of the complete closure of the common suction line by said throttling valve means,

said inlet apertures being arranged within the area of the individual suction lines near the respective cylinders.

3. A suction line installation for a mixture-com ressing injection-type internal combustion engine having a plurality of cylinders, comprising:

a common suction line including throttle valve means for selectively adjusting the amount of combustion air to be supplied to the engine during normal operation,

individual suction lines operatively connecting said common suction line with the individual cylinders, said individual suction lines being devoiod of any throttle valves and including individual fuel injection means disposed therein,

and means independent of said fuel injection means for supplying combustion air during the idling speed operation of the engine including inlet apertures for the combustion air provided within the individual suction lines so that the combustion air is able to enter into said individual suction lines only through said inlet apertures during idling speed operation by reason of the complete closure of the common suction line by said throttling valve means,

and an idling-speed common suction line in which terminate said inlet apertures and provided with a common adjustable air inlet means.

4. A suction line installation for a mixture-compressing injection-type internal combustion engine having a plurality of cylinders, comprising:

a common suction line including throttle valve means for selectively adjusting the amount of combustion air to be supplied to the engine during normal operation, individual suction lines operatively connecting said common suction line with the individual cylinders, said individual suction lines being devoid of any throttle valves and including individual fuel injection means disposed therein, and means independent of said fuel injection means for supplying combustion air during the idling speed operation of the engine including inlet apertures for the combustion air provided within the individual suction lines so that the combustion air is able to enter into said individual suction lines only through said inlet apertures during idling speed operation by reason of the complete closure of the common suction line by said throttling valve means, said inlet apertures being arranged within the area of the individual suction lines near the respective cylinders, and an idling-speed common suction line in which terminate said inlet apertures and provided with a common adjustable air inlet means. 5. A suction line system for an internal combustion engine having cylinder means, comprising:

common suction line means, throttling valve means in said common suction line means for selectively adjusting the amount of combustion air to be supplied to the engine during normal operation, individual suction line means operatively connecting said common suction line means with the cylinder means and including individual fuel injection means disposed therein, and means independent of said fuel injection means for supplying combustion air during the idling speed operation of the engine to said individual suction line means substantially completely in by-passing relationship with respect to the common suction line means. 6. A suction line system for an internal combustion engine having cylinder means, comprising:

common suction line means, throttling valve means in said common suction line means for selectively adjusting the amount of combustion air to be supplied to the engine during normal operation and operable to substantially completely block the entrance of air through the common suction line means in the fully closed position thereof, individual suction line means operatively connecting said common suction line means with the cylinder means and including individual fuel injection means disposed therein, and means independent of said fuel injection means disposed in said individual suction line means near the cylinder means for supplying combustion air during the idling speed operation of the engine to said individual suction line means substantially completely in by-passing relationship with respect to the common suction line means. 7. A suction line system for an internal combustion engine having a plurality of cylinder means, comprising:

common suction line means, throttling valve means in said common suction line means for selectively adjusting the amount of combustion air to be supplied to the engine during normal operation and operable to substantially completely block the entrance of air through the common suction line means in the fully closed position thereof, individual suction line means operatively connecting said common suction line means with the cylinder means and including individual fuel injection means disposed therein, and means independent of said fuel injection means disposed in said individual suction line means near the cylinder means for supplying combustion air during the idling speed operation of the engine to said individual suction line means substantially completely in by-passing relationship with respect to the common suction line means including a single adjusting member for adjusting the idling-speed air quantity supplied to all of said cylinder means.

8. A suction line system for an internal combustion engine having a plurality of cylinder means, comprising:

common suction line means,

throttling valve means in said common suction line means for selectively adjusting the amount of combustion air to be supplied to the engine during normal operation,

individual suction line means operatively connecting said common suction line means with the cylinder means and including individual fuel injection means disposed therein,

and means independent of said fuel injection means for supplying combustion air during the idling speed operation of the engine to said individual suction line means substantially completely in by-passing relationship with respect to the common suction line means including a single adjusting .member for adjusting the idling-speed quantity supplied to all of said cylinder means.

9. In a suction line system for a mixture-compressing injection-type internal combustion engine having a plurality of cylinders, which includes a common suction line provided with a throttling valve for selectively adjusting the amount of combustion air to be supplied to the engine during normal operation thereof and a plurality of individual suction lines operatively connecting the common suction line with the individual cylinders and including individual fuel injection means, whereby the individual suction lines are without throttling valves,

the improvement essentially consisting of combustion air inlet apertures provided within the individual suction lines and independently disposed from said fuel injection means, whereby the combustion air is able to reach the individual suction lines only through the inlet apertures during idling speed operation of the engine by reason of the substantially complete closure of the common suction line by said throttling valve.

10. In a suction line system for a mixture-compressing injection-type internal combustion engine having a plurality of cylinders, which includes a common suction line provided with a throttling valve for selectively adjusting the amount of combustion air to be supplied to the engine during normal operation thereof and a plurality of individual suction lines operatively connecting the common suction line with the individual cylinders and including individual fuel injection means, whereby the individual, suction lines are Without throttling valves,

the improvement essentially consisting of combustion air inlet apertures provided within the individual suction lines and independently disposed from said fuel injection means, whereby the combustion air is able to reach the individual suction lines only through the inlet apertures during idling speed operation of the engine by reason of the substantially complete closure of the common suction line by said throttling valve,

the inlet apertures being arranged within the area of the individual suction lines near the respective cylinders.

11. In a suction line system for a mixture-compressing injection-type internal combustion engine having a plurality of cylinders, which includes a common suction line provided With a throttling valve for selectively adjusting the amount of combustion air to be supplied to the engine during normal operation thereof and a plurality of individual suction lines operatively connecting the common suction line with the individual cylinders and including the improvement essentially consisting of combustion individual fuel injection means, whereby the individual air inlet apertures provided within the individual sucsuetion lines are without throttling valves, tion lines and independently disposed from said fuel the improvement essentially consisting of combustion injection means, whereby the combustion air is able air inlet apertures provided within the individual suction lines and independently disposed from said fuel injection means, whereby the combustion air is able to reach the individual suction lines only through the inlet apertures during idling speed operation of the engine by reason of the substantially complete closure of the common suction line by said throttling valve,

21 common idling speed suction line which is in communication with the individual suction lines through the air inlet apertures, and a common manually adjustable air inlet for said common idling speed suction line.

12. In a suction line system for a mixture-compressing injection-type internal combustion engine having a pluralto reach the individual suction lines only through the inlet apertures during idling speed operation of the engine 'by reason of the substantially complete closure of the common suction line by said throttling valve,

the inlet apertures being arranged within the area of the individual suction lines near the respective cylinders,

a common idling speed suction line which is in com- References Cited by the Examiner ity of cylinders, which includes a common suction line 20 provided with a throttling valve for selectively adjusting UNITED STATES PATENTS the amount of combustion air to be sup lied to th engine 2,157,034 5/39 Tice 125-139.17 during normal operation thereof and a plurality of i 2,833,260 5/58 DOlZa 125139.17 dividual suction lines operatively connecting th om n 2,860,616 11/58 Dermoud 125-l39.17

suction line with the individual cylinders and including 2 fuel injection means, whereby the individual suction lines are without throttling valves,

KARL J. ALBRECHT, Primary Examiner. 

1. A SUCTION LINE INSTALLATION FOR A MIXTURE-COMPRESSING INJECTION-TYPE INTERNAL COMBUSTION ENGINE HAVING A PLURALITY OF CYLINDERS, COMPRISING: A COMMON SUCTION LINE INCLUDING THROTTLE VALVE MEANS FOR SELECTIVELY ADJUSTING THE AMOUNT OF COMBUSTION AIR TO BE SUPPLIED TO THE ENGINE DURING NORMAL OPERATION, INDIVIDUAL SUCTION LINES OPERATIVELY CONNECTING SAID COMMON SUCTION LINE WITH THE INDIVIDUAL CYLINDERS, SAID INDIVIDUAL SUCTION LINES BEING DEVOID OF ANY THROTTLE VALVES AND INCLUDING INDIVIDUAL FUEL INJECTION MEANS INDEPENDENT THEREIN, AND MEANS INDEPENDENT OF SAID FUEL INJECTION MEANS FOR SUPPLYING COMBUSTION AIR DURING THE IDLING SPEED OPERATION OF THE ENGINE INCLUDING INLET APERTURES FOR THE COMBUSTION AIR PROVIDED WITHIN THE INDIVIDUAL SUCTION LINES SO THAT THE COMBUSTION AIR IS ABLE TO ENTER INTO SAID INDIVIDUAL SUCTION LINES ONLY THROUGH SAID INLET APERTURES DURING IDLING SPEED OPERATION BY REASON OF THE COMPLETE CLOSURE OF THE COMMON SUCTION LINE BY SAID THROTTLING VALVE MEANS. 